I have a mercruiser 5.0L with an alpha drive that I bought new in 1999 in a 23 ft cuddy cabin fishing boat, and am thinking of changing the intake manifold and carb. I have had nothing but problems with the stock 2 barrel mercruiser carb since I have had the boat. I am thinking of going with a edelbrock performer manifold and 600cfm carb. The mechanic I use at the boat shop advised me againt going with a four barrel carb, but then he makes good money every time I have it rebuilt.I found the intake for $169 and the carb for $299 which is cheaper than a new two barrel merc carb.And before you ask, yes I fog the carb and run stabil in the fuel every time I put the boat up. Is this a good replacement? Will I see any good performance gains? Will I need to change the throttle bracket or can I use the existing one? I would appriciate any help or information that anyone has.